1,135 research outputs found
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Using Ontology Research in Semantic Web Applications
In the light of improving the World Wide Web, researchers are working towards the Semantic Web. Ontologies and ontology-based applications are its basic ingredients. Several ontological environments, categorizations and methodologies can be found in the literature. This paper shows how we have investigated the state of the art in these areas in an ontology building process that is the basis for an application developed at the later stage in an events organisation domain
Derivation and verification of empirical catchment response time equations for medium to large catchments in South Africa
Published ArticleDespite uncertainties and errors in measurement, observed peak discharges are the best estimate of the true peak discharge from a
catchment. However, in ungauged catchments, the catchment response time is a fundamental input to all methods of estimating
peak discharges; hence, errors in estimated catchment response time directly impact on estimated peak discharges. In South
Africa, this is particularly the case in ungauged medium to large catchments where practitioners are limited to use empirical
methods that were calibrated on small catchments not located in South Africa. The time to peak (TP), time of concentration (TC)
and lag time (TL) are internationally the most frequently used catchment response time parameters and are normally estimated
using either hydraulic or empirical methods. Almost 95% of all the time parameter estimation methods developed internationally
are empirically based. This paper presents the derivation and verification of empirical TP equations in a pilot scale study using 74
catchments located in four climatologically different regions of South Africa, with catchment areas ranging from 20 km2 to
35 000 km2. The objective is to develop unique relationships between observed TP values and key climatological and
geomorphological catchment predictor variables in order to estimate catchment TP values at ungauged catchments. The results
show that the derived empirical TP equation(s) meet the requirement of consistency and ease of application. Independent
verification tests confirmed the consistency, while the statistically significant independent predictor variables included in the
regressions provide a good estimation of catchment response times and are also easy to determine by practitioners when required
for future applications in ungauged catchments. It is recommended that the methodology used in this study should be expanded
to other catchments to enable the development of a regional approach to improve estimation of time parameters on a
national-scale. However, such a national-scale application would not only increase the confidence in using the suggested
methodology and equation(s) in South Africa, but also highlights that a similar approach could be adopted internationally
Are estimates of catchment response time inconsistent as used in current flood hydrology practice in South Africa?
Published ArticleCatchment response time parameters are one of the primary inputs required when design floods, especially in ungauged catchments, need to be estimated. The time of concentration (TC) is the most frequently used time parameter in flood hydrology practice, and continues to find application in both event-based methods and continuous hydrological models. Despite the widespread use of the TC, a unique working definition and equation(s) are currently lacking in South Africa. This paper presents the results of the direct and indirect TCestimation for three sets of catchments, which highlight their inherent variability and inconsistencies. These case studies demonstrate that estimates of TC, using different equations, may differ from one another by up to 800%. As a consequence of this high variability and uncertainty, we recommend that, for design hydrology and calibration purposes, observed TCvalues should be estimated using both the average catchment TCvalue, which is based on the event means, and a linear catchment response function. This approach is not only practical, but also proved to be objective and consistent in the study areas investigated in this paper
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Integration with Ontologies
One of todayâs hottest IT topics is integration, as bringing together information from different sources and structures is not completely solved. The approach outlined here wants to illustrate how ontologies [Gr93] could help to support the integration process
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Corrigendum: a decision framework for considering climate change adaptation in biodiversity conservation planning
Entrances and exits: changing perceptions of primary teaching as a career for men
Original article can be found at: http://www.informaworld.com/smpp/title~content=t713640830~db=all Copyright Informa / Taylor and Francis. DOI: 10.1080/03004430802352087The number of men in teaching has always been small, particularly in early childhood, but those that do come into teaching usually do so for the same reasons as women, namely enjoyment of working with children, of wanting to teach and wanting to make a difference to children's lives. However, in two separate studies, the authors have shown that on beginning teacher training in 1998, and at the point of leaving the profession in 2005, men and women tend to emphasise different concerns. This article will explore those differences and seek possible explanations for how men's views of teaching might be changing over time.Peer reviewe
Academic self-concept, gender and single-sex schooling
This paper assesses gender differences in academic self-concept for a cohort of children born in 1958 (the National Child Development Study). We address the question of whether attending single-sex or co-educational schools affected studentsâ perceptions of their own academic abilities (academic self-concept). Academic selfconcept was found to be highly gendered, even controlling for prior test scores. Boys had higher self-concepts in maths and science, and girls in English. Single-sex schooling reduced the gender gap in self-concept, while selective schooling was linked to lower academic self-concept overall
Insights from genetic studies of cerebral palsy
Cohort-based whole exome and whole genome sequencing and copy number variant (CNV) studies have identified genetic etiologies for a sizable proportion of patients with cerebral palsy (CP). These findings indicate that genetic mutations collectively comprise an important cause of CP. We review findings in CP genomics and propose criteria for CP-associated genes at the level of gene discovery, research study, and clinical application. We review the published literature and report 18 genes and 5 CNVs from genomics studies with strong evidence of for the pathophysiology of CP. CP-associated genes often disrupt early brain developmental programming or predispose individuals to known environmental risk factors. We discuss the overlap of CP-associated genes with other neurodevelopmental disorders and related movement disorders. We revisit diagnostic criteria for CP and discuss how identification of genetic etiologies does not preclude CP as an appropriate diagnosis. The identification of genetic etiologies improves our understanding of the neurobiology of CP, providing opportunities to study CP pathogenesis and develop mechanism-based interventions
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